José Barraza Molina, science communicator at the Center for Climate and Resilience Research (CR2), and René Garreaud, deputy director of CR2 and professor at the Department of Geophysics (DGF) of the University of Chile.
The news of a tornado in Puerto Varas has left no one indifferent, with multiple and serious impacts, dominating morning shows and national news. This phenomenon reminds us that Chile experiences a range of extreme meteorological events capable of causing severe socio-environmental impacts, such as flash floods, atmospheric rivers, droughts, and tornadoes.
At 9:31 AM on Sunday, May 25, the Chilean Meteorological Service (DMC) issued advisory A190/2025, warning of the “development of convective storms with tornadogenic characteristics” for the Biobío and La Araucanía regions. The tornado struck that afternoon (3:10 PM) in Puerto Varas, in the province of Llanquihue, at which time DMC issued an alert (AAA003/2025) for these storms. This predictive ability—still limited in general—is notable, considering that ten years ago, no one was even talking about these events. How was this progress achieved?
The swarm of tornadoes in late May 2019 triggered research into their causes and conditions, and since then, several scientific articles on tornadoes have been published, some led by CR2 researchers in collaboration with many other scientists (Barret et al., 2020; Aránguiz et al., 2020; Marín et al., 2021; Vicencio et al., 2021; Marín et al., 2024; Caballero-Morán & Rondanelli, 2024). This knowledge was rapidly transferred to the operational environment and now underpins current DMC forecasts.
The transfer from the lab (academia) to the real world (operations), as illustrated by Sunday’s events, is an example of a virtuous cycle that occasionally occurs in meteorology. Until a “new phenomenon” is studied and named, it essentially doesn’t exist—it remains anecdotal.
Let’s take a closer look.
In the case of tornadoes, the first recorded event likely occurred in the 16th century, with many others throughout Chile’s history, including one in Santiago in the 19th century. However, it was only from 2019 onward that the phenomenon began to be rigorously systematized scientifically, with tornado and waterspout alerts now issued by official institutions.
Another example is the 0 °C isotherm height—the level at which snow turns to rain—a storm-related feature studied since the early 1990s following the Santiago landslide in May 1993 (Garreaud & Rutllant, 1996). Today, this concept appears in the media and in official weather alerts, as it strongly influences the hydrological response to precipitation (Garreaud, 2013).
Atmospheric rivers are another longstanding meteorological phenomenon that can have either beneficial or adverse effects. When these high-moisture air filaments move west to east—zonal atmospheric rivers (Garreaud et al., 2024)—they strike the Andes perpendicularly and often trigger floods and landslides. The 2017 Santa Lucía landslide, the rare summer winter storm in January 2021, and the massive flooding in south-central Chile in June 2023 were all caused by zonal atmospheric rivers, spurring scientific interest and media coverage.
From a climatological perspective, terms like “megadrought” and “megafires” also originated in science and have deeply influenced society and decision-makers. CR2 has played an active role in this kind of “scientific impact” on public discourse.
Researching extreme phenomena and achieving their recognition—both socially (in media) and institutionally (via alerts)—is only a first step. More accurate forecasts require improved observation systems, including weather radars and state-of-the-art instruments. Equally crucial, reducing public risk in the face of meteorological hazards means forecasts must activate clear, effective, and well-known emergency plans.
References
Aránguiz, R., Saez, B., Gutiérrez, G., Oyarzo-Vera, C., Nuñez, E., Quiñones, C., … & Bull, M. T. (2020). Damage assessment of the May 31st, 2019, Talcahuano tornado, Chile. International Journal of Disaster Risk Reduction, 50, 101853.
Barrett, B. S., Marin, J. C., & Jacques-Coper, M. (2020). A multiscale analysis of the tornadoes of 30–31 May 2019 in south-central Chile. Atmospheric Research, 236, 104811.
Caballero‐Morán, V., & Rondanelli, R. (2025). Tornado seasonality in central‐southern Chile. Geophysical Research Letters, 52(1), e2024GL110900.
Centro de Ciencia del Clima y la Resiliencia. (26 de mayo de 2025). Tornado de Puerto Varas coincide con la estacionalidad en la que se esperan este tipo de fenómenos en Chile. CR2.cl. https://www.cr2.cl/tornado-de-puerto-varas-coincide-con-la-estacionalidad-en-la-que-se-esperan-este-tipo-de-fenomenos-en-chile/
Departamento de Geofísica. (19 de diciembre de 2017). Aluvión en Villa Santa Lucía y su relación con un Río Atmosférico. Dgf.uchile.cl. http://www.dgf.uchile.cl/noticias/140021/aluvion-en-villa-santa-lucia-y-su-relacion-con-un-rio-atmosferico
Garreaud, R., & J. Rutllant. (1996). Análisis meteorológico de los aluviones de Antofagasta y Santiago de Chile en el periodo 1991-1993. Atmósfera. 9, 251-271.
Garreaud, R. (2013). Warm winter storms in Central Chile. Journal of Hydrometeorology, 14(5), 1515-1534.
Garreaud, R., Aldunce, P., Araya, G., Blanco, G., Boisier, JP., Bozkurt, D., Carmona, A., Christie, D., Farías, L., Gallardo, L., Galleguillos, M., González, M., Herrera, P., Huneeus, N., Jiménez, D., Lara, A., Latoja, D., Lillo, G., Masotti, Í., Moraga, P., Nahuelhual, L., Paredes, P., Ossandón, J., Rojas, M., Urquiza, A., Yévenes, M., & Zambrano, M. (2015). Informe a la Nación. La megasequía 2010-2015: Una lección para el futuro. Centro de Ciencia del Clima y la Resiliencia (CR)2, (ANID/FONDAP/15110009), 84 pp. Disponible en https://www.cr2.cl/megasequia/
Garreaud, R. (24 de abril de 2017). Análisis: La altura de la isoterma 0°C durante tormentas en Chile central | (CR)2. Centro de Ciencia del Clima y la Resiliencia CR2. https://www.cr2.cl/la-altura-de-la-isoterma-0c-durante-tormentas-en-chile-central-por-rene-garreaud/
Garreaud, R., & Vergara, I. (19 de marzo de 2021). Análisis: ¿Una tormenta de invierno en pleno verano? Entendiendo el extraordinario evento de finales de enero de 2021 en Chile central | (CR)2. Centro de Ciencia del Clima y la Resiliencia CR2. https://www.cr2.cl/analisis-una-tormenta-de-invierno-en-pleno-verano-entendiendo-el-extraordinario-evento-de-finales-de-enero-de-2021-en-chile-central-cr2/
Garreaud, R., Jacques-Coper, M., Marín, JC., Narváez, & D.A. (2024). Atmospheric Rivers in South-Central Chile: Zonal and Tilted Events. Atmosphere, 406, DOI: https://doi.org/10.3390/atmos15040406
González, M.E., Sapiains, R., Gómez-González, S., Garreaud, R., Miranda, A., Galleguillos, M., Jacques, M., Pauchard, A., Hoyos, J., Cordero, L., Vásquez, F., Lara, A., Aldunce, P., Delgado, V., Arriagada, Ugarte, A.M., Sepúlveda, A., Farías, L., García, R., Rondanelli, R.,J., Ponce, R.,Vargas, F., Rojas, M., Boisier, J.P., C., Carrasco, Little, C., Osses, M., Zamorano, C., Díaz-Hormazábal, I., Ceballos, A., Guerra, E., Moncada, M., Castillo, I . (2020). Incendios forestales en Chile: causas, impactos y resiliencia. Centro de Ciencia del Clima y la Resiliencia (CR)2, (ANID/FONDAP/15110009), 84 pp. Disponible en https://www.cr2.cl/incendios/
Marín, J. C., Barrett, B. S., & Pozo, D. (2021). The tornadoes of 30–31 May 2019 in south-central Chile: Sensitivity to topography and SST. Atmospheric Research, 249, 105301.
Marín, J. C., Gutiérrez, F., Gensini, V. A., Barrett, B. S., Pozo, D., Jacques-Coper, M., & Veloso-Aguila, D. (2024). Climatological aspects of notable tornado events in Chile. Monthly Weather Review, 152(8), 1803-1819.
Rondanelli, R., & Barraza, J. (10 de julio de 2023). Análisis (CR)2 | Chile, país de tornados. Centro de Ciencia del Clima y la Resiliencia CR2. https://www.cr2.cl/analisis-cr2-chile-pais-de-tornados/
Vicencio, J., Rondanelli, R., Campos, D., Valenzuela, R., Garreaud, R., Reyes, A., … & Nicora, G. (2021). The chilean tornado outbreak of May 2019: synoptic, mesoscale, and historical contexts. Bulletin of the American Meteorological Society, 102(3), E611-E634.
